1988 Volkswagen Cabrio Fuel System

I am buying a GAS powered VW Cabrio from a dealership; they took the vehicle on a trade in. The dealership said the vehicle was fine when they made the trade, they were taking it out for a test drive with a perspective buyer and it broke down. They said they pulled the fuel filter off and he claims that tons of stuff was plugged in the filter. They also said the tank was probably full of the same. I read one form where the person answering questions said "not to run the tanks dry"; I am wondering if the fuel tank will have to be removed or even worst, the fuel system replaced. What is the chance, the dirt got to the injectors? If you can offer me some advice that would be great because, I am contemplating on buying the vehicle.